A light emitting device, such as a light emitting diode or a laser diode, using a group III-V or II-VI compound semiconductor material may emit light having various colors, such as red, green, blue and ultraviolet light, as the result of advances in thin film growth technology and materials for the device. Also, the light emitting device may emit white light with high efficiency using phosphor or through combination of colors. Furthermore, the light emitting device has advantages of lower power consumption, semi-permanent lifespan, rapid response time, safety and environmental friendliness, when compared with conventional light sources, such as a fluorescent lamp or an incandescent lamp.
Consequently, application of the light emitting device is expanded to a transmission module of an optical communication apparatus, a light emitting diode backlight that can replace a cold cathode fluorescence lamp constituting the backlight of a liquid crystal display apparatus, a white light emitting diode lighting apparatus which can replace a fluorescent lamp or an incandescent lamp, an automobile head light, and a signal light.